Anti-Two Block
© PAT
Rev. - 12/18/00 // CSH.
190118_-.DOC
15
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Disconnect switch(es) from boom tip junction box and measure the resistance between A and B to check the
function of the anti-two block switch. Check all connected switches main and extension.
This checks the function of the Anti-Two Block switch.
Switch closed = 0Ohms (weight or flag installed)
Switch open => 1 Megaohm (weight or flag removed)
Connect switches to the correct position.
Refer to Drawing 1 and 9.
Replace faulty anti-two block switch assembly.
Refer to Drawing 1.
Correct?
No
Turn off system power. Check the the signal in the main boom tip junction box, measure the resistance
between terminals 5 and 6. the junction box must be connected as follows:
!
a switch or by-pass plug connected to the two 2 pin receptacles
Switch closed = 4.7KOhms (weight or flag installed)
Switch open => 1 Megaohm (weight or flag removed)
Refer to Drawing 1 and 9.
Check wire connections in boom nose box.
Replace junction box.
Refer to Drawing 1.
Correct?
No
Yes
Check cable reel for damaged cable.
Replace cable reel.
Refer to Drawing 1and 10.
Correct?
No
Yes
Turn off system power. Check the the signal in the 14 pin receptacle on the cable reel.
measure the resistance between terminals E and F.
Switch closed = 4.7KOhms (weight or flag installed)
Switch open => 1 Megaohm (weight or flag removed)
Refer to Drawing 1.
Check cable assembly between cable
reel and CU for damaged cable.
Replace cable assembly.
Refer to Drawing 1.
Yes
